Electrical method for the detection and separation of coins from substitutes



March 10, 193i. T. n. BoTToME 1,795,287

ELECTRICAL METHOD FOR THE DETECTION AND SEPARATION OF COINS FROM SUBSTITUTES Filed Feb. 20, 1950 @hw/QW Patented Mar. 10, 1931 'UNITED STATES lPATENT OFFICE TURNER IBOTTOME, OF INDIANAPOLIS, INDIANA ELECTRICAL METHOD FOR THE DETECTION AND SEPARATION F COINS FROM'. SUBSTITUTES Application led February 20, 1930. Serial No. 430,066.

good coins.

In carrying this invention into eiect, refp erence to the accompanying drawing will assist in explanation, as follows:

Fig. 1 is a section on line 1--1 of Fig. 2

showing a plunger 6 1n com receiving position. Fig. 2 1s an end elevation showing some of the parts in section. Fig. 3 is a view similar to Fig. 1, but showing the plunger carrying a coin which is being pressed against electrical contacts.

In Fig. 1 a coin receptacle 1 permits a coin 2 to be dropped into an inlet coin chute 3, and if the coin is of normal diameter it will be retained by the path of sizing anvils 4,

These anvils are rigidly supported to protrude from the end of the plunger 6. They are horizontally set a certain distance apart so that a coin or disk, smaller in diameter than the size of the coin for which the anvils are adjusted, will pass between the anvls and be rejected from the apparatus through the continuation of chute 3.

The plunger is suitably supported and is adapted to be moved forward by applied pressure, then by a spring or other means to return to its coin receiving position when the pressure is released. A spring or gravity controlled pawl 5 normally hangs in a pendant position near one edge of the inlet chute and is adapted to prevent the coin from bouncing oil of the anvils. It also assists in holding the coin in place while being pushed towards the variable resistance contacts 7 The space surrounding t-he dotted lines 2 in Fig. 1 constitutes a testing chamber and it isto show the position of thecoin just as it reaches the contacts 7 illustrating that electrical connection is made by the coin with these contacts before it has been pressed against the contacts 8 and 9.

The contacts 7 may be of any number found most suitable and they may be arranged in any pattern most desirable depending upon the size and character of the surface of the coin for which they are to be used. In the drawing five of the contacts 7 are shown. They are rigidly supported in the insulating block 10 and are provided with adjustment so that their free ends may all be arranged in a lane parallel to the plane of a smooth face disk that may be pressed against them so that Iall five contacts will make electrical connection with the surface of the disk.

The block 10'is of resilient insulating material in order to provide a certain amount of resiliency to the contacts 7, each of which is adapted to individually spring back one or two thousandths of an inch when pressure is applied, then to return to their normal position when the pressure is released. Other means of providing this resiliency and for adjusting its amount have certain advantages over the method shown in the drawing. However, the screws 7 permit the adjustment of the protrusion of the contact point (or free end) from theblock 10. The nut is a means for holding the adjustment as well as for adjusting the amount of resiliency since the tighter' the nut is drawn, the less vspring-back is provided for the Contact. The block 10 is conveniently held in position and guided by means of the adjustable spring supports 11 which are adapted to normally hold the block in position as shown in Fig. 1, so that'a coin when pressed against the contacts 7 will touch them but not touch the contacts-8 and 9 until the coin has pushed the block 10 back a sufficient distance as shown in Fig. 3.

The contacts 8 and 9 are each flexibly supported in any convenient manner that adapts them to freely penetrate suitable holes in the block 10,-adjustment being provided so that their free ends will not make electrical con- 1 nection with a coin or disk until the contacts 7 have made their connection.

In Fig. 2 the contacts 7 are shown in electrical connection, each of which is connected to one terminal of a separate fixed resistance 12 which may be of any suitable ohmic resistance, but each of them are of approximately equal ohmic value. The other terminals of the resistances 12 Aare all joined together and are placed inconnection with one terminal of the battery 13. The circuit then passes through the battery to its terminal 14 and thence through the relay A and on to the circuit closing-contact 9 which makes contact with the coin 2 and the coin carries the current to the contacts 7 incompletion of the At the same time a relay variable circuit. non-variable or balancing circuit is made through rela A, beginning at the coin 2 through the balancing resistance contact 8, the balancing resistance 16 thence to terminal 17 of the battery 15 to the common battery terminal 14 and on through relay A to the circuit-closing contact 9 and the coin in completion of the circuit.

The balancing resistance 16 is of ohmic resistance just equaling the combined parallel resistance of the five resistances 12 when all five contacts 7 make connection with a disk 2. An electrical balance or neutralization of two currents is made through relay A when the combined resistances 12 in parallel are just equal to the resistance of the balancing resistance 16 when the batteries 13 and 15 are connected in series and of equal voltage and internal resistance and when having a common terminal between them in connection with one terminal of relay A the other terminal being in connection with the disk and contacts in. completion of the circuit. This arrangement gives a current in one direction through relay A from one battery, and a current in the opposite direction through relay A from the other battery, the relay is adjusted so that it is not energized when these two currents are approximately equal and opposite in direction. But if only four or less of the contacts 7 make connection with a coin, then the -combined resistance in parallel of the four resistances 12 will be greater than that of the balancing resistance 16, hence a greater current will iow through resistance 16 circuit than flows in the opposite direction through resistance 12 circuit and relay A will become energized by the difference between the two opposed currents resulting in an excess current from resistance 16 circuit.

In operation, a smooth face coin or check of normal size is inserted in receptacle 1. It will drop into chute 3 and be supported upon the sizing anvils 4 and be centrally located on the end of plunger 6. The plunger 1s then pushed by hand or by other applied pressure and presses the disk 2 against the contacts 7 as shown in Fig. 3l whereby all five of them make electrical connection with the disk, placing all five of the resistances 12 in circuit with the associated battery and with relay A, also in connection with the circuit closing-contact 9 which acts to completi` the variable resistance 12 circuit. 'lhe disk at the same time completes the balancing resistance 16 circuit through its associated battery, thence through the balancing resistance contact 8 through the disk and the circuitclosing contact 9, thence through relay A to the common battery terminal 14, the electrical currents through the two circuits will be equal and opposite in direction and there will not be an excess current flowing through relay A, hence it will not become energized, then when the pressure is released upon the \p lunger 6, it will return to its normal coin receiving position and during its return stroke the pawls 5 and 5 assume a position, as in Fig. 3, to prevent the coin from following the plunger. The block 10 is also returned to its normal position by means of the springs 11, placing the disk in position to fall by gravity into the coin deflecting exit chute 18 into which. it drops striking the coin deiiector 19, which may be a pin as shown or other suitable device, which is adapted to obstruct the branch chute 2O and to deflect and direct the smooth face coin or disk to fall through branch chute 21 rejected from the apparatus.

If a coin or coin substitute of normal diameter having a central hole in it is dropped upon the sizing anvils 4 and is pressed against the contacts on block 10, no electrical contact will be made with the circuit-closing contact 9, because it is adapted to penetrate a central hole in the block 10, and the anvils 4 have been vertically adjusted to support the disk 2 coaxially with reference to the circuit-closing contact 9, hence the contact will penetrate the hole in the disk 2 when pressure is applied against the contacts 7 suiiciently to push the block 10 back to its limit, therefore no electrical connection will be made placing relay A in circuit with the batteries, then upon release of pressure the disk will fall into chute 18, be deflected by the obstruction 19 and fall through branch chute 21 rejected.

A non-metallic disk of normal size when dropped into the coin chute 3 will rest upon the anvils 4 and when pressed against the contacts in the block 10 will act as an insulator, no electrical connection will bey made, hence the coin defiector 19 will remain in the coin rejecting position, and upon release of pressure upon the plunger, the non-metallic disk will fall out of the apparatus rejected.

When a good coin of normal size is inserted in receptacle 1`it will fall upon and be retained in position upon the sizing anvils 4, the coin is then pressed against the contacts 7, the pressure being continued until the pawls 5 and 5 engage with the coin thus permitting the contacts 8 and 9 to make electrical connections with the coin. The surface of a coin ordinarily consists of a pattern in relief interspersed with depressions in the surface,

and since the contacts 7 are' rigidly fixed in a -one of the batteries through .place t plane all of them are not likely to make connection with the highest relief portions of the pattern on the surface of the coin. In practice one orv more of them is reasonably certain not to make an electrical connection with the coin because of the probability of being in a position over a depression in the pattern, which depression if over one or two thousandths of an inch deep will be of suicient depth to prevent electrical connection being made, in which event less than five of theresistances 12 will be placed in the variable resistance circuit, an excess electrical current will flow through the balancing resistance circuit because of the lack of balance between the two opposing currents, resulting in the energizing of relay A and the closing of the contact 23, thereby completing a circuit from the coin deflector ma net B which becomes energized to dise coin deector 24 and to move the obstructing pin 19 into the position 19 which acts to obstruct the branch coin chute 21, as soon as this position is'reached. The detent 22 engages with the notch 25 to hold the coin deector in the coin retaining position until the coin drops down chute 18 after pressure has been released from the coin, it then falls striking the obstruction 19 which delects and directs the coin within the associated apparatus through vthe branch coin chute 20. The coin in passing through chute 20 is adapted to.de press the contact 26 or otherwise to close a contact 26 which is a means of completing a circuit through the detent magnet C and with one of the batteries, which energizes` magnet C to release the detent 22 permitting the coin deflector 24; to regain its normal coin rejectin position.

elay A is shown in the drawing and is described as a means for relaying or providing a greater current for producing mechanical work than would ordinarily be expected of a comparatively small current flowing through a circuit of resistances, but as-a matter of fact, the strength of current passing through relay A when the two opposing circuits are unbalanced may easily be made of sufficient strength to directly operate the coin deiector, doing away entirely with magnets B and C by providing a suitable detent for holding the deflector in position until the coin passes through the branch chute 20, vthe weight or momentum of the coin being suiicient to release the detent as the coin passes through the chute. While the devices B and C are unnecessary, they are practical and offer a means of easily illustrating the invention.

1 claim:

1. The coin detector comprising a check testing chamber, a check inlet chute communicating with said chamber, a plunger having a pair of sizing anvils thereon and adapted to support a check of the proper size against the face of the plunger, the plunger in its normal position being adapted to receive a check from said inlet chute and upon said anvils, a check exit chute in alignment with the inlet chute and the anvils and adapted to receive and reject checks which do not bridge the anvils, means for reciprocating the plunger, a block of insulating material across the end of the chamber opposite the plunger, a set of variable resistance contacts projecting from said block, said contacts being in a plane which is parallel to the face of the plunger, a balancing resistance contact -\and a circuit closing contact projecting thru said block, the two latter being adapted to contact with a check carried by the plunger at substantially the inward limit of the plunger movement, the variable resistance contacts being adjusted to contact with said check slightly in advance of the other two contacts, said check being positioned on said anvils to ace said contacts, said plunger and its movement being in alignment with the block and contacts, a third chute located substantially at the inward extremity of the plunger stroke and adapted to'receive checks from the plunger after said checks have made contact with some or all of said contacts, a set of pawls situated intermediate the extremities of the plunger movement and adapted to remove all checks from the sizing anvils upon movement of the plunger toward its normal position, means communicating with the third chute for receiving and retaining roper checks and means also communicating with the third chute forreceiving and rejecting improper or spurious checks, a check defiector situated within the third chute and at the junction of said check receiving means, a relay adapted to actuate said delector, a balancing resistance having one terminal connected to the balancing resistance contact, a set of lequal resistances individually connected to the variable resistance contacts and having their other terminals connected to a common circuit and adapted to act as a single variable resistance, a set of batteries adapted to connect said variable and balancing resistances in opposed circuits, the circuit closing contact being connected to one terminal of the relay, the other relay terminal being connected with said batteries and in circuit with the opposed resistances and their contacts.

2. rlhe structure defined in claim 1 having a check defiector controlling mechanism comprising a notch in said deector, a detent coacting with said notch in the actuated or check retaining position of said deflector, means situated in the check retaining means and actuable by a retained check to release said deiector from said detent and means to return the deiector to its normal or check rejecting position.

3. rlhe structure deined in claim 1 with the circuit closing contact positioned through said block co-axially With the axis of a check of normal size in anvil supported check testing position upontlie end of said plunger.

4. The structure defined in claim l with the check deector positioned normally to deect a check in the check rejecting direction and adapted to direct a check in the retaining direction when actuated by said relay, the relay being actuated by means of a coin having a surface in relief being pressed against said projecting contacts when one or more of the variable resistance contacts fails to electrically connect with said coin, substantially as described.

TURNER D. BOTTGME. 

